Optically clear plastics that demonstrate confined crystallization are useful for various applications including holographic data storage. Materials which exhibit the ability to undergo a threshold phase change and concomitant change in refractive index have been reported as a potential method to read and write holograms in a suitable storage media. Certain block copolymers are known to provide materials which will phase separate and exhibit confined crystallization. However, a commercially viable material has yet to be discovered. Accordingly, there is a need for improved materials which are easily processed and can transition between a crystalline phase and an amorphous phase while maintaining a high degree of optical clarity, through which enhanced holographic data storage applications can be achieved.